Much recent research has focused on 2D:4D(the ratio of the lengths of the second to fourth
manual digits) as a predictor of the degree of expression of sexually dimorphic and other
sex-hormonemediated traits. However, published findings are often contradictory or subject to
various methodological problems.
In the present study, the differences of MRT(Mental Rotation Ability) scores of young children
between gender groups and between 2D:4D(left hand, right hand) groups were tested. As results,
means of MRT scores showed no significant difference between for the gender groups and for the
2D:4D group of left hand. However, for the 2D:4D group of right hand, significant differences
were founded. These results mean who influenced more testosterone hormone showed higher MRT
score than others regardless their gender. The recent 2D:4D literature in light of these findings and
their implications for sex differences in special education of young children were discussed.